The present invention relates to forming of warheads by isostatic compaction, and more particularly to forming complex patterns on the inside diameter of isostatically compacted warheads.
Cold isostatic pressing is one process of choice for forming components from particulate materials. In cold isostatic pressing, a powder charge is loaded into an elastomeric mold (called a "bag"). The bag is sealed after filling, positioned within the containment vessel, and exposed to a pressurized fluid environment.
The bag may be part of the pressure vessel (dry bag process) or may be a separate, independent unit placed within the pressure vessel (wet bag process). In either case, a mandrel may be included within the bag to aid in forming details on the resulting pressed material.
In operation, the fluid is pressurized and in turn applies a hydrostatic pressure to the bag. The bag thus acts as a hermetically sealed pressure transfer membrane between the fluid environment and the loaded material charge. If a mandrel is included inside the bag, then the pressure compacts the powder against the mandrel. Upon completion of the pressing process, the vessel and bag are opened and the pressed part (called a "preform") is separated from the mandrel. The preform is then thermally treated, sintered, to increase strength through diffusion bonding, and may also be hot isostatically pressed to final density.
However, removal of the mandrel from the preform may present special difficulty when parts of unusual, complex, or tapered interior are formed by such processing. For this reason, complex patterns are usually machined rather than pressed onto the interior of those parts requiring such patterns.
In the abovementioned application Ser. No. 07,697,120, incorporated herein by reference, a method and apparatus for making an improved missile warhead are disclosed wherein high density particulate materials are incorporated into a compacted-powder warhead body during its formation. The high density inclusions are preferably compatible with the material of the warhead body, and are preferably incorporated in an ordered array into the ID of the finished warhead by any of several disclosed. methods. A missile having a warhead incorporating such invention preferably has a proximity detonation capability whereby the included high density particles can act as armor-piercing projectiles on the order of the size and weight of the high density material inclusions. As a result, targets can be severely damaged without direct hits, thus increasing the lethality of such weapons. The above warheads are typically pressed from titanium powder.
It is therefore an object of the present invention to provide a warhead formed by cold isostatic processing and having improved lethality.
It is another object of the present invention to provide a warhead body which can accommodate material inclusions.